The New World has 340 species in 27 genera, which equates to a third of the World fauna. Adults of most species are ball-rollers, and they shape carrion or dung into balls that are rolled away and buried at a distance from the food source. Key to genera: Halffter and Martínez 1977. Biology: Gordon and Cartwright 1974; Halffter and Halffter 1989.